PCIe 4.0 will make auxiliary power cables for GPUs obsolete

It’s been nearly six years since the PCI Special Interest Group (PCI-SIG) released the base specification for PCIe 3.0. With its successor just around the bend, interest in the new specification is certainly heating up in the hardware community.

Update (8/25): Earlier this week we reported on the upcoming PCI Express 4.0 standard, with information from Tom's Hardware suggesting the updated specification would support up to 300 watts of power through the PCIe slot. It turns out this information was inaccurate. More information here.

You’ve likely heard by now that PCIe 4.0 will offer up 16 gigatransfers per second (GTps), up from just eight afforded by today’s standard. That’s in addition to a host of other changes to enhance efficiency but it’s a new revelation regarding power delivery that has people talking today.

As you may know, the PCIe 3.0 specification is certified for up to 75 watts of power delivery through the connector. That’s usually enough for most add-in cards although higher-end graphics cards demand far more juice which comes via dedicated lines straight from the power supply.

With PCIe 4.0, the PCI-SIG is significantly boosting the amount of power supplied to the slot. In an interview with Tom’s Hardware, PCI-SIG Vice President Richard Solomon said PCIe 4.0 would deliver a minimum of 300 watts via its slot and perhaps as much as 500 watts. That means you could run today’s most demanding GPUs without the need for dedicated power cables, resulting in a tidy installation with less airflow restriction.

It’s also worth mentioning that the new connector will be backward compatible with PCIe 3.0 cards although newer PCIe 4.0-compliant cards can’t be used on older PCIe 3.0 boards.

Solomon also detailed a new standard called OCuLink that’ll facilitate the use of high-end graphics cards and solid state drives both inside and outside of a PC (think of it as PCIe-over-cable).

The final PCIe 4.0 specification should be completed by the end of the year.

It'll be nice to have a couple less cables traveling through the case (and instead going into the motherboard), but delivering an additional 225-425 watts of power through the connector sounds kind of scary. QC for motherboard power delivery will have to be much tighter ha ha ha...

Yeah, my liberal arts ed is overwhelmed as well -- one thing heavy cables do well is transfer a Lot o' power, but better minds than mine are saying that passing up to 500 more Watts through traces is going to be ok as well.
As mobos have Famously failed in the past due to cost-savings, etc., it does make me go hmm..
wish DBZ still posted, I'd like to hear their take..

My guess would be the GPU connectors will be adapted and moved to the motherboard, Initially. Then the PSU connection will be altered to accommodate the extra 1500W's the PCIe slots may or may not need. If you ask me, I think things are fine the way they are. Power delivery is fine for the mass majority, no need in changing anything.

I see the spec should be completed by the end of the year. Any hint of when we might start seeing new hardware on the market that implements it?

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If they really finish this year then we might see some high end motherboards as soon as Q1-Q2 2017 and more mainstream stuff late 2017 early 2018. it also depends on if amd and nvidia have some cards ready in 2017.